Subject: SCSI DAT tape drives.
To: None <tech-userlevel@NetBSD.ORG>
From: Gerryt <>
List: tech-userlevel
Date: 03/04/1998 14:33:06
Arch: i386

We have occasional backup problems with 4 mm DATS. What happens is we see this
Mar  1 12:56:28 amon /netbsd: st0(ahc1:4:0):  Check Condition on opcode 0x1
Mar  1 12:56:28 amon /netbsd:     SENSE KEY:  Unit Attention
Mar  1 12:56:28 amon /netbsd:      ASC/ASCQ:  Power On, Reset, or Bus Device
Reset Occurred

When you see this message only a cold boot clears up the problem as tapes are
no longer accesible.

This is using an Adaptec 2940 UW controller. In the past we have tried

controller NCR to AHA
scsi cable
DAT drives
OS upgrades from 1.2.1 to 1.3

In short everything but the motherboard has been swapped out with different H/W
or S/W. Still we see the above message at random times - approximately every
7-14 days. 

Are all scsi tape drives this screwy? Do they work better if we say, give it
its OWN controller?